Modern internal combustion engines must meet stringent emission standards that include limits on the amount of soot and nitrogen oxides (NOx) that may be emitted. Many engines now utilize aftertreatment systems to reduce engine-out emissions to regulatory levels before release to the atmosphere. Such aftertreatment systems may operate most effectively within a certain internal temperature range, and particularly above a minimum internal temperature. However, the temperature of an aftertreatment system may be outside of the desired operating temperature range, specifically upon startup of the engine and under certain engine operating conditions when load on the engine is diminished. Therefore, a need remains for systems, apparatus, and methods to maintain the temperature of aftertreatment systems within a desired temperature range.